The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Jean Dubuisson - One of the best experts on this subject based on the ideXlab platform.
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Antigenicity and B-epitope mapping of hepatitis C Virus Envelope protein E2
Biochemistry (Moscow) Supplement Series B: Biomedical Chemistry, 2009Co-Authors: T. I. Kuzmina, Jean Dubuisson, L. V. Olenina, M. A. Sanzhakov, T. E. Farafonova, T. V. Abramihina, B. N. Sobolev, E. F. KolesanovaAbstract:Immunogenicity for laboratory animals (rabbits and mice) of the whole hepatitis C Virus Envelope proteins and their conserved as well as hypervariable HVR1 sites has been investigated. Rabbit immune responses to HCV Envelope proteins (both single E2 and E1E2 heterodimer) were shown to be much more efficient than murine immune responses. Rabbit immunization with E2 protein caused formation of antibodies to several highly conserved linear B-epitopes of this protein as well as to the N-terminal fragment of the hypervariable region HVR1. Epitopes in the CR2 region were determined for the first time. There was cross-reactivity between the N-terminal fragment of the protein E2 hypervariable region HVR1 and the octapeptide fragment of the protein E1 conserved region CR1, which shared four identical amino acid residues.
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characterization of functional hepatitis c Virus Envelope glycoproteins
Journal of Virology, 2004Co-Authors: Anne Op De Beeck, Laurence Cocquerel, Cecile Voisset, Birke Bartosch, Yann Ciczora, Zhenyong Keck, Steven K H Foung, Francoisloic Cosset, Jean DubuissonAbstract:Hepatitis C Virus (HCV) encodes two Envelope glycoproteins, E1 and E2, that assemble as a noncovalent heterodimer which is mainly retained in the endoplasmic reticulum. Because assembly into particles and secretion from the cell lead to structural changes in viral Envelope proteins, characterization of the proteins associated with the virion is necessary in order to better understand how they mature to be functional in Virus entry. There is currently no efficient and reliable cell culture system to amplify HCV, and the Envelope glycoproteins associated with the virion have therefore not been characterized yet. Recently, infectious pseudotype particles that are assembled by displaying unmodified HCV Envelope glycoproteins on retroviral core particles have been successfully generated. Because HCV pseudotype particles contain fully functional Envelope glycoproteins, these Envelope proteins, or at least a fraction of them, should be in a mature conformation similar to that on the native HCV particles. In this study, we used conformation-dependent monoclonal antibodies to characterize the Envelope glycoproteins associated with HCV pseudotype particles. We showed that the functional unit is a noncovalent E1E2 heterodimer containing complex or hybrid type glycans. We did not observe any evidence of maturation by a cellular endoprotease during the transport of these Envelope glycoproteins through the secretory pathway. These Envelope glycoproteins were recognized by a panel of conformation-dependent monoclonal antibodies as well as by CD81, a molecule involved in HCV entry. The functional Envelope glycoproteins associated with HCV pseudotype particles were also shown to be sensitive to low-pH treatment. Such conformational changes are likely necessary to initiate fusion.
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Topology of hepatitis C Virus Envelope glycoproteins.
Reviews in medical virology, 2003Co-Authors: Anne Op De Beeck, Jean DubuissonAbstract:Hepatitis C Virus encodes two Envelope glycoproteins, E1 and E2, that are released from a polyprotein precursor after cleavage by host signal peptidase(s). These proteins contain a large N-terminal ectodomain and a C-terminal transmembrane domain, and they assemble as a noncovalent heterodimer. The transmembrane domains of hepatitis C Virus Envelope glycoproteins have been shown to be multifunctional: (1) they are membrane anchors, (2) they bear ER retention signals, (3) they contain a signal sequence function, and (4) they are involved in E1-E2 heterodimerisation. Due to these multiple functions, the topology adopted by these transmembrane domains has given rise to much controversy. They are less than 30 amino acid residues long and are composed of two stretches of hydrophobic residues separated by a short segment containing one or two fully conserved positively charged residues. The presence of a signal sequence function in the C-terminal half of the transmembrane domains of E1 and E2 had suggested that these domains are composed of two membrane spanning segments. However, the two hydrophobic stretches are too short to make two membrane spanning alpha-helices. These discrepancies can now be explained by a dynamic model, based on experimental data, describing the early steps of the biogenesis of hepatitis C Virus Envelope glycoproteins. In this model, the transmembrane domains of E1 and E2 form a hairpin structure before cleavage by a signal peptidase, and a reorientation of the second hydrophobic stretch occurs after cleavage to produce a single membrane spanning domain.
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Topological changes in the transmembrane domains of hepatitis C Virus Envelope glycoproteins.
The EMBO journal, 2002Co-Authors: Laurence Cocquerel, F. Penin, Anne Op De Beeck, M. Lambot, J. Roussel, D. Delgrange, A. Pillez, C. Wychowski, Jean DubuissonAbstract:Hepatitis C Virus proteins are synthesized as a polyprotein cleaved by a signal peptidase and viral proteases. The behaviour of internal signal sequences at the C-terminus of the transmembrane domains of hepatitis C Virus Envelope proteins E1 and E2 is essential for the topology of downstream polypeptides. We determined the topology of these transmembrane domains before and after signal sequence cleavage by tagging E1 and E2 with epitopes and by analysing their accessibility in selectively permeabilized cells. We showed that, after cleavage by signal peptidase in the endoplasmic reticulum, the C-terminal orientation of these transmembrane domains changed from luminal to cytosolic. The dynamic behaviour of these transmembrane domains is unique and it is linked to their multifunctionality. By reorienting their C-terminus toward the cytosol and being part of a transmembrane domain, the signal sequences at the C-terminus of E1 and E2 contribute to new functions: (i) membrane anchoring; (ii) E1E2 heterodimerization; and (iii) endoplasmic reticulum retention.
J. Dubuisson - One of the best experts on this subject based on the ideXlab platform.
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Antigenicity and B-epitope mapping of hepatitis C Virus Envelope protein E2
Biomeditsinskaia khimiia, 2009Co-Authors: T I Kuz'mina, J. Dubuisson, L. V. Olenina, M. A. Sanzhakov, T. E. Farafonova, B. N. Sobolev, T V Abramikhina, E. F. KolesanovaAbstract:Immunogenicity for laboratory animals (rabbits and mice) of the whole hepatitis C Virus Envelope proteins and their conserved as well as hypervariable HVR1 sites has been investigated. Rabbit immune responses to HCV Envelope proteins (both single E2 and E1E2 heterodimer) were shown to be much more efficient than murine immune responses. Upon the immunization of the rabbit with E2 protein, antibodies to several highly conserved linear B-epitopes of this protein as well as to the N-terminal fragment of the hypervariable region HVRI were formed. Epitopes in the CR2 region were determined for the first time. Cross-reactivity was revealed between the N-terminal fragment of the protein E2 hypervariable region HVRI and the octapeptide fragment of the protein E1 conserved region CR1, which shared four identical amino acid residues.
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Topological changes in the transmembrane domains of hepatitis C Virus Envelope glycoproteins.
EMBO Journal, 2002Co-Authors: Laurence Cocquerel, F. Penin, A. Opdebeeck, M. Lambot, J. Roussel, D. Delgrange, A. Pillez, C. Wychowski, J. DubuissonAbstract:Hepatitis C Virus proteins are synthesized as a polyprotein cleaved by a signal peptidase and viral proteases. The behaviour of internal signal sequences at the C-terminus of the transmembrane domains of hepatitis C Virus Envelope proteins E1 and E2 is essential for the topology of downstream polypeptides. We determined the topology of these transmembrane domains before and after signal sequence cleavage by tagging E1 and E2 with epitopes and by analysing their accessibility in selectively permeabilized cells. We showed that, after cleavage by signal peptidase in the endoplasmic reticulum, the C-terminal orientation of these transmembrane domains changed from luminal to cytosolic. The dynamic behaviour of these transmembrane domains is unique and it is linked to their multifunctionality. By reorienting their C-terminus toward the cytosol and being part of a transmembrane domain, the signal sequences at the C-terminus of E1 and E2 contribute to new functions: (i) membrane anchoring; (ii) E1E2 heterodimerization; and (iii) endoplasmic reticulum retention.Hepatitis C Virus proteins are synthesized as a polyprotein cleaved by a signal peptidase and viral proteases. The behaviour of internal signal sequences at the C-terminus of the transmembrane domains of hepatitis C Virus Envelope proteins E1 and E2 is essential for the topology of downstream polypeptides. We determined the topology of these transmembrane domains before and after signal sequence cleavage by tagging E1 and E2 with epitopes and by analysing their accessibility in selectively permeabilized cells. We showed that, after cleavage by signal peptidase in the endoplasmic reticulum, the C-terminal orientation of these transmembrane domains changed from luminal to cytosolic. The dynamic behaviour of these transmembrane domains is unique and it is linked to their multifunctionality. By reorienting their C-terminus toward the cytosol and being part of a transmembrane domain, the signal sequences at the C-terminus of E1 and E2 contribute to new functions: (i) membrane anchoring; (ii) E1E2 heterodimerization; and (iii) endoplasmic reticulum retention.
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The transmembrane domains of hepatitis C Virus Envelope glycoproteins E1 and E2 play a major role in heterodimerization.
The Journal of biological chemistry, 2000Co-Authors: A. Op De Beeck, F. Penin, R. Montserret, Sandrine Duvet, Laurence Cocquerel, René Cacan, B Barberot, M. Le Maire, J. DubuissonAbstract:Oligomerization of viral Envelope proteins is essential to control Virus assembly and fusion. The transmembrane domains (TMDs) of hepatitis C Virus Envelope glycoproteins E1 and E2 have been shown to play multiple functions during the biogenesis of E1E2 heterodimer. This makes them very unique among known transmembrane sequences. In this report, we used alanine scanning insertion mutagenesis in the TMDs of E1 and E2 to examine their role in the assembly of E1E2 heterodimer. Alanine insertion within the center of the TMDs of E1 or E2 or in the N-terminal part of the TMD of E1 dramatically reduced heterodimerization, demonstrating the essential role played by these domains in the assembly of hepatitis C Virus Envelope glycoproteins. To better understand the alanine scanning data obtained for the TMD of E1 which contains GXXXG motifs, we analyzed by circular dichroism and nuclear magnetic resonance the three-dimensional structure of the E1-(350-370) peptide encompassing the N-terminal sequence of the TMD of E1 involved in heterodimerization. Alanine scanning results and the three-dimensional molecular model we obtained provide the first framework for a molecular level understanding of the mechanism of hepatitis C Virus Envelope glycoprotein heterodimerization.
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The transmembrane domains of hepatitis C Virus Envelope glycoproteins E1 and E2 play a major role in heterodimerization.
Journal of Biological Chemistry, 2000Co-Authors: A. Opdebeeck, F. Penin, R. Montserret, Sandrine Duvet, Laurence Cocquerel, René Cacan, B Barberot, M. Lemaire, J. DubuissonAbstract:Oligomerization of viral Envelope proteins is essential to control Virus assembly and fusion. The transmembrane domains (TMDs) of hepatitis C Virus Envelope glycoproteins E1 and E2 have been shown to play multiple functions during the biogenesis of E1E2 heterodimer. This makes them very unique among known transmembrane sequences. In this report, we used alanine scanning insertion mutagenesis in the TMDs of E1 and E2 to examine their role in the assembly of E1E2 heterodimer. Alanine insertion within the center of the TMDs of E1 or E2 or in the N-terminal part of the TMD of E1 dramatically reduced heterodimerization, demonstrating the essential role played by these domains in the assembly of hepatitis C Virus Envelope glycoproteins. To better understand the alanine scanning data obtained for the TMD of E1 which contains GXXXG motifs, we analyzed by circular dichroism and nuclear magnetic resonance the three-dimensional structure of the E1-(350-370) peptide encompassing the N-terminal sequence of the TMD of E1 involved in heterodimerization. Alanine scanning results and the three-dimensional molecular model we obtained provide the first framework for a molecular level understanding of the mechanism of hepatitis C Virus Envelope glycoprotein heterodimerization.Oligomerization of viral Envelope proteins is essential to control Virus assembly and fusion. The transmembrane domains (TMDs) of hepatitis C Virus Envelope glycoproteins E1 and E2 have been shown to play multiple functions during the biogenesis of E1E2 heterodimer. This makes them very unique among known transmembrane sequences. In this report, we used alanine scanning insertion mutagenesis in the TMDs of E1 and E2 to examine their role in the assembly of E1E2 heterodimer. Alanine insertion within the center of the TMDs of E1 or E2 or in the N-terminal part of the TMD of E1 dramatically reduced heterodimerization, demonstrating the essential role played by these domains in the assembly of hepatitis C Virus Envelope glycoproteins. To better understand the alanine scanning data obtained for the TMD of E1 which contains GXXXG motifs, we analyzed by circular dichroism and nuclear magnetic resonance the three-dimensional structure of the E1-(350-370) peptide encompassing the N-terminal sequence of the TMD of E1 involved in heterodimerization. Alanine scanning results and the three-dimensional molecular model we obtained provide the first framework for a molecular level understanding of the mechanism of hepatitis C Virus Envelope glycoprotein heterodimerization.
Laurence Cocquerel - One of the best experts on this subject based on the ideXlab platform.
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characterization of functional hepatitis c Virus Envelope glycoproteins
Journal of Virology, 2004Co-Authors: Anne Op De Beeck, Laurence Cocquerel, Cecile Voisset, Birke Bartosch, Yann Ciczora, Zhenyong Keck, Steven K H Foung, Francoisloic Cosset, Jean DubuissonAbstract:Hepatitis C Virus (HCV) encodes two Envelope glycoproteins, E1 and E2, that assemble as a noncovalent heterodimer which is mainly retained in the endoplasmic reticulum. Because assembly into particles and secretion from the cell lead to structural changes in viral Envelope proteins, characterization of the proteins associated with the virion is necessary in order to better understand how they mature to be functional in Virus entry. There is currently no efficient and reliable cell culture system to amplify HCV, and the Envelope glycoproteins associated with the virion have therefore not been characterized yet. Recently, infectious pseudotype particles that are assembled by displaying unmodified HCV Envelope glycoproteins on retroviral core particles have been successfully generated. Because HCV pseudotype particles contain fully functional Envelope glycoproteins, these Envelope proteins, or at least a fraction of them, should be in a mature conformation similar to that on the native HCV particles. In this study, we used conformation-dependent monoclonal antibodies to characterize the Envelope glycoproteins associated with HCV pseudotype particles. We showed that the functional unit is a noncovalent E1E2 heterodimer containing complex or hybrid type glycans. We did not observe any evidence of maturation by a cellular endoprotease during the transport of these Envelope glycoproteins through the secretory pathway. These Envelope glycoproteins were recognized by a panel of conformation-dependent monoclonal antibodies as well as by CD81, a molecule involved in HCV entry. The functional Envelope glycoproteins associated with HCV pseudotype particles were also shown to be sensitive to low-pH treatment. Such conformational changes are likely necessary to initiate fusion.
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Topological changes in the transmembrane domains of hepatitis C Virus Envelope glycoproteins.
The EMBO journal, 2002Co-Authors: Laurence Cocquerel, F. Penin, Anne Op De Beeck, M. Lambot, J. Roussel, D. Delgrange, A. Pillez, C. Wychowski, Jean DubuissonAbstract:Hepatitis C Virus proteins are synthesized as a polyprotein cleaved by a signal peptidase and viral proteases. The behaviour of internal signal sequences at the C-terminus of the transmembrane domains of hepatitis C Virus Envelope proteins E1 and E2 is essential for the topology of downstream polypeptides. We determined the topology of these transmembrane domains before and after signal sequence cleavage by tagging E1 and E2 with epitopes and by analysing their accessibility in selectively permeabilized cells. We showed that, after cleavage by signal peptidase in the endoplasmic reticulum, the C-terminal orientation of these transmembrane domains changed from luminal to cytosolic. The dynamic behaviour of these transmembrane domains is unique and it is linked to their multifunctionality. By reorienting their C-terminus toward the cytosol and being part of a transmembrane domain, the signal sequences at the C-terminus of E1 and E2 contribute to new functions: (i) membrane anchoring; (ii) E1E2 heterodimerization; and (iii) endoplasmic reticulum retention.
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Topological changes in the transmembrane domains of hepatitis C Virus Envelope glycoproteins.
EMBO Journal, 2002Co-Authors: Laurence Cocquerel, F. Penin, A. Opdebeeck, M. Lambot, J. Roussel, D. Delgrange, A. Pillez, C. Wychowski, J. DubuissonAbstract:Hepatitis C Virus proteins are synthesized as a polyprotein cleaved by a signal peptidase and viral proteases. The behaviour of internal signal sequences at the C-terminus of the transmembrane domains of hepatitis C Virus Envelope proteins E1 and E2 is essential for the topology of downstream polypeptides. We determined the topology of these transmembrane domains before and after signal sequence cleavage by tagging E1 and E2 with epitopes and by analysing their accessibility in selectively permeabilized cells. We showed that, after cleavage by signal peptidase in the endoplasmic reticulum, the C-terminal orientation of these transmembrane domains changed from luminal to cytosolic. The dynamic behaviour of these transmembrane domains is unique and it is linked to their multifunctionality. By reorienting their C-terminus toward the cytosol and being part of a transmembrane domain, the signal sequences at the C-terminus of E1 and E2 contribute to new functions: (i) membrane anchoring; (ii) E1E2 heterodimerization; and (iii) endoplasmic reticulum retention.Hepatitis C Virus proteins are synthesized as a polyprotein cleaved by a signal peptidase and viral proteases. The behaviour of internal signal sequences at the C-terminus of the transmembrane domains of hepatitis C Virus Envelope proteins E1 and E2 is essential for the topology of downstream polypeptides. We determined the topology of these transmembrane domains before and after signal sequence cleavage by tagging E1 and E2 with epitopes and by analysing their accessibility in selectively permeabilized cells. We showed that, after cleavage by signal peptidase in the endoplasmic reticulum, the C-terminal orientation of these transmembrane domains changed from luminal to cytosolic. The dynamic behaviour of these transmembrane domains is unique and it is linked to their multifunctionality. By reorienting their C-terminus toward the cytosol and being part of a transmembrane domain, the signal sequences at the C-terminus of E1 and E2 contribute to new functions: (i) membrane anchoring; (ii) E1E2 heterodimerization; and (iii) endoplasmic reticulum retention.
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The transmembrane domains of hepatitis C Virus Envelope glycoproteins E1 and E2 play a major role in heterodimerization.
The Journal of biological chemistry, 2000Co-Authors: A. Op De Beeck, F. Penin, R. Montserret, Sandrine Duvet, Laurence Cocquerel, René Cacan, B Barberot, M. Le Maire, J. DubuissonAbstract:Oligomerization of viral Envelope proteins is essential to control Virus assembly and fusion. The transmembrane domains (TMDs) of hepatitis C Virus Envelope glycoproteins E1 and E2 have been shown to play multiple functions during the biogenesis of E1E2 heterodimer. This makes them very unique among known transmembrane sequences. In this report, we used alanine scanning insertion mutagenesis in the TMDs of E1 and E2 to examine their role in the assembly of E1E2 heterodimer. Alanine insertion within the center of the TMDs of E1 or E2 or in the N-terminal part of the TMD of E1 dramatically reduced heterodimerization, demonstrating the essential role played by these domains in the assembly of hepatitis C Virus Envelope glycoproteins. To better understand the alanine scanning data obtained for the TMD of E1 which contains GXXXG motifs, we analyzed by circular dichroism and nuclear magnetic resonance the three-dimensional structure of the E1-(350-370) peptide encompassing the N-terminal sequence of the TMD of E1 involved in heterodimerization. Alanine scanning results and the three-dimensional molecular model we obtained provide the first framework for a molecular level understanding of the mechanism of hepatitis C Virus Envelope glycoprotein heterodimerization.
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The transmembrane domains of hepatitis C Virus Envelope glycoproteins E1 and E2 play a major role in heterodimerization.
Journal of Biological Chemistry, 2000Co-Authors: A. Opdebeeck, F. Penin, R. Montserret, Sandrine Duvet, Laurence Cocquerel, René Cacan, B Barberot, M. Lemaire, J. DubuissonAbstract:Oligomerization of viral Envelope proteins is essential to control Virus assembly and fusion. The transmembrane domains (TMDs) of hepatitis C Virus Envelope glycoproteins E1 and E2 have been shown to play multiple functions during the biogenesis of E1E2 heterodimer. This makes them very unique among known transmembrane sequences. In this report, we used alanine scanning insertion mutagenesis in the TMDs of E1 and E2 to examine their role in the assembly of E1E2 heterodimer. Alanine insertion within the center of the TMDs of E1 or E2 or in the N-terminal part of the TMD of E1 dramatically reduced heterodimerization, demonstrating the essential role played by these domains in the assembly of hepatitis C Virus Envelope glycoproteins. To better understand the alanine scanning data obtained for the TMD of E1 which contains GXXXG motifs, we analyzed by circular dichroism and nuclear magnetic resonance the three-dimensional structure of the E1-(350-370) peptide encompassing the N-terminal sequence of the TMD of E1 involved in heterodimerization. Alanine scanning results and the three-dimensional molecular model we obtained provide the first framework for a molecular level understanding of the mechanism of hepatitis C Virus Envelope glycoprotein heterodimerization.Oligomerization of viral Envelope proteins is essential to control Virus assembly and fusion. The transmembrane domains (TMDs) of hepatitis C Virus Envelope glycoproteins E1 and E2 have been shown to play multiple functions during the biogenesis of E1E2 heterodimer. This makes them very unique among known transmembrane sequences. In this report, we used alanine scanning insertion mutagenesis in the TMDs of E1 and E2 to examine their role in the assembly of E1E2 heterodimer. Alanine insertion within the center of the TMDs of E1 or E2 or in the N-terminal part of the TMD of E1 dramatically reduced heterodimerization, demonstrating the essential role played by these domains in the assembly of hepatitis C Virus Envelope glycoproteins. To better understand the alanine scanning data obtained for the TMD of E1 which contains GXXXG motifs, we analyzed by circular dichroism and nuclear magnetic resonance the three-dimensional structure of the E1-(350-370) peptide encompassing the N-terminal sequence of the TMD of E1 involved in heterodimerization. Alanine scanning results and the three-dimensional molecular model we obtained provide the first framework for a molecular level understanding of the mechanism of hepatitis C Virus Envelope glycoprotein heterodimerization.
Jakub K. Simon - One of the best experts on this subject based on the ideXlab platform.
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Serostatus cutoff levels and fold increase to define seroresponse to recombinant vesicular stomatitis Virus - Zaire Ebola Virus Envelope glycoprotein vaccine: An evidence-based analysis.
Vaccine, 2020Co-Authors: Joseph M. Antonello, Rebecca J. Grant-klein, Rick Nichols, Stephen B. Kennedy, Sheri A. Dubey, Jakub K. SimonAbstract:Abstract The recombinant vesicular stomatitis Virus – Zaire Ebola Virus Envelope glycoprotein (rVSVΔG-ZEBOV-GP) vaccine is a live recombinant vesicular stomatitis Virus (VSV) where the VSV G protein is replaced with ZEBOV-GP. To better understand the immune response after receiving the rVSVΔG-ZEBOV-GP vaccine, the current analyses evaluated different definitions of seroresponse that differentiate vaccine and placebo recipients enrolled in a placebo-controlled clinical trial (PREVAIL; NCT02344407) in which a subset of the study participants had elevated baseline titers. Alternative values for serostatus cutoff (SSCO; 200–500 EU/mL) and/or fold rise (two- to five-fold) were applied to compare their ability to distinguish between participants receiving rVSVΔG-ZEBOV-GP or placebo. The results indicate that an SSCO of 200 EU/mL can be used to define seropositivity at baseline (i.e. pre-vaccination). The use of dual criteria of the same SSCO (200 EU/mL) together with a two-fold rise in antibody level from baseline provided the definition of seroresponse that maximized the statistical significance between vaccine recipients and placebo recipients post-vaccination. Clinical trial registration: NCT02344407.
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six month safety data of recombinant vesicular stomatitis Virus zaire ebola Virus Envelope glycoprotein vaccine in a phase 3 double blind placebo controlled randomized study in healthy adults
The Journal of Infectious Diseases, 2017Co-Authors: Scott A Halperin, Jakub K. Simon, Jose R Arribas, Richard E Rupp, Charles P Andrews, Matthew T Onorato, Jason Martin, Frans A HelmondAbstract:Background: This study (NCT02503202) evaluated the safety of recombinant vesicular stomatitis Virus-Zaire Ebola Virus Envelope glycoprotein vaccine (rVSVΔG-ZEBOV-GP). Methods: Overall, 1197 subjects were randomized 2:2:2:2:1; 1194 were vaccinated with 1 dose of 1 of 3 lots of rVSVΔG- ZEBOV-GP (2 × 107 plaque-forming units [pfu], n = 797; combined-lots group), a single high-dose lot of rVSVΔG-ZEBOV-GP (1 × 108 pfu, n = 264; high-dose group), or placebo (n = 133). Daily temperatures and adverse events (AEs) were recorded days 1 to 42 postvaccination. Solicited AEs included injection-site AEs from days 1 to 5, and joint pain, joint swelling, vesicular lesions (blisters), and rashes from days 1 to 42. Serious AEs (SAEs) were recorded through 6 months postvaccination. Results: Fever (≥38.0°C) was observed in 20.2% of combined lots (3.2% with ≥39.0°C), 32.2% of high-dose (4.3% with ≥39.0°C), and 0.8% of placebo (0.8% with ≥39.0°C). Incidences of AEs of interest (days 1-42) were arthralgia (17.1% combined lots, 20.4% high-dose, 3.0% placebo), arthritis (5.1% combined lots, 4.2% high-dose, 0.0% placebo), and rash (3.8% combined lots, 3.8% high-dose, 1.5% placebo). Twenty-one SAEs and 2 deaths were reported, all assessed by investigators as unrelated to vaccine. Conclusions: rVSVΔG-ZEBOV-GP was generally well-tolerated, with increased rates of injection-site and systemic AEs compared to placebo, and no vaccine-related SAEs or deaths. These findings support the use of rVSVΔG-ZEBOV-GP vaccine in persons at risk for Ebola Virus disease. Clinical Trials Registration: NCT02503202.
Daved H Fremont - One of the best experts on this subject based on the ideXlab platform.
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crystal structure of the japanese encephalitis Virus Envelope protein
Journal of Virology, 2012Co-Authors: Vincent C Luca, Jad P Abimansour, Christopher A Nelson, Daved H FremontAbstract:Japanese encephalitis Virus (JEV) is the leading global cause of viral encephalitis. The JEV Envelope protein (E) facilitates cellular attachment and membrane fusion and is the primary target of neutralizing antibodies. We have determined the 2.1-A resolution crystal structure of the JEV E ectodomain refolded from bacterial inclusion bodies. The E protein possesses the three domains characteristic of flaviVirus Envelopes and epitope mapping of neutralizing antibodies onto the structure reveals determinants that correspond to the domain I lateral ridge, fusion loop, domain III lateral ridge, and domain I-II hinge. While monomeric in solution, JEV E assembles as an antiparallel dimer in the crystal lattice organized in a highly similar fashion as seen in cryo-electron microscopy models of mature flaviVirus virions. The dimer interface, however, is remarkably small and lacks many of the domain II contacts observed in other flaviVirus E homodimers. In addition, uniquely conserved histidines within the JEV serocomplex suggest that pH-mediated structural transitions may be aided by lateral interactions outside the dimer interface in the icosahedral virion. Our results suggest that variation in dimer structure and stability may significantly influence the assembly, receptor interaction, and uncoating of virions.
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crystal structure of the west nile Virus Envelope glycoprotein
Journal of Virology, 2006Co-Authors: Grant E Nybakken, Christopher A Nelson, Beverly R Chen, Michael S Diamond, Daved H FremontAbstract:The Envelope glycoprotein (E) of West Nile Virus (WNV) undergoes a conformational rearrangement triggered by low pH that results in a class II fusion event required for viral entry. Herein we present the 3.0-A crystal structure of the ectodomain of WNV E, which reveals insights into the flaviVirus life cycle. We found that WNV E adopts a three-domain architecture that is shared by the E proteins from dengue and tick-borne encephalitis Viruses and forms a rod-shaped configuration similar to that observed in immature flaviVirus particles. Interestingly, the single N-linked glycosylation site on WNV E is displaced by a novel α-helix, which could potentially alter lectin-mediated attachment. The localization of histidines within the hinge regions of E implicates these residues in pH-induced conformational transitions. Most strikingly, the WNV E ectodomain crystallized as a monomer, in contrast to other flaviVirus E proteins, which have crystallized as antiparallel dimers. WNV E assembles in a crystalline lattice of perpendicular molecules, with the fusion loop of one E protein buried in a hydrophobic pocket at the DI-DIII interface of another. Dimeric E proteins pack their fusion loops into analogous pockets at the dimer interface. We speculate that E proteins could pivot around the fusion loop-pocket junction, allowing virion conformational transitions while minimizing fusion loop exposure.
